String feed mechanism



y 1941- D. J. DUNCAN ET AL 2,249,377

STRING FEED MECHANISM Filed Sept. 29, 1939 3 Sheets-Sheet l Inventors D. J, DUNCAN R D. PROPHET,

July 15, 1941. D. J. DUNCAN ETAL 1 77 STRING FEED MECHANISM Filed Sept.- 29, 193?) 3 Sheets-Sheet 2 1), J DUNCAN RD. PROPHET,

By 2mm ma $9M, 3m

Attorneys July 15, 1941. D. J. DUNCAN ET AL 2,249,377

STRING FEED MECHANISM Filed Sept. 29, 1939 3 Sheets-Sheet 5 Inventor: R D. J; DUNCAN R.D.PR0PHET,

Attorneys Patented July 15, 1941 UNITED STATES FATE T srlcs Dallas, Tex. I Application September 29, 1939, Serial No. 297,166 4 Claims. (Cl. 112-2) This invention relates to a string feed mechanism especially adapted for laying string into a hem of fabric employed in the making of cloth bags, so that each bag constructed from the hemmed fabric will be provided with a tying string for the closing of the bag. The primary object of the present invention is the provision of a device of the above stated character which operates in conjunction with a cloth folder or hemmer on a sewing machine and is operated in timed relation with the cloth feeding mechanism of said sewing machine so that a surplus amount of string will be laid in or arranged in the hem of the fabric whereby on the cutting of said fabric into pieces of selected lengths for the making of bags, each piece of fabric will have in the hem thereof string of sufficient length which when extended from the ends of the hem will be of a length to permit convenient tying of the ends of the string to close the mouth of the bag.

Another object of this invention is the provision of a device of the above stated character which will successfully lay in a surplus amount of string within the hem of the fabric employed in the making of bags and which amount of string laid in the hem may be varied through the adjustment of the device and further a device of this character will permit such work to be rapidly carried out and provide a large saving in time in the construction of finished bags heretofore re.- quiring manual labor in the threading of the. string through the hem after the making of the hem in the fabric.

With these and other objects in .view, the invention consists in certain novel features of construction, combination and arrangement of parts to be hereinafter more fully described and claimed.

For a complete understanding of our invention, reference is to be had to the following description and accompanying drawings, in which Figure 1 is a top plan view illustrating a string feed mechanism mounted on a fragmentary portion of a sewing machine and showing the same in combination with a hemmer on said sewing machine and operated by the cloth feed mechanism of the sewing machine and which is indicated in the major portion thereof by dotted lines.

Figure 2 is a side elevation illustrating the invention mounted on a fragmentary portion of a sewing machine.

Figure 3 is an enlarged top plan view showing machine.

with a hem;

view taken on'the line Figure 7 is a fragmentary plan view partly in section showing the hemmed fabric with a tying string laid therein.

Figure 8 is a transverse sectional view through the hem of the fabric and the tying string.

Figure 9 is an enlarged fragmentary sectional view showing the operating means for the cloth feed mechanism of the machine and showing the connection of the present invention thereto.

Figure 10 is a transverse sectional view showing a modification of the present invention wherein several strings are fed by the device into the hem. Figure 11 is a fragmentary plan view partly in section of the hemmed fabric with the double strings arranged within the hem.

Referring in detail to the drawings, the numeral 5 indicates a fragmentary portion of a sewing machine used in the sewing of fabric employed inthe making of fabric bags used for many purposes such as mailing bags, bags for containing articles of merchandise for sale, and the like. The sewing'machine forms no part of the present invention and only a portion thereof is shown in the'drawings for the purpose of illustrating the application of the present invention to a sewing The cloth feed mechanism of the sewing machine is indicated generally by the character 6 and as well known in this art is for the purpose of feeding the cloth relative tothe needle and presser foot of the sewing machine and has an operating mechanism indicated generally by the character 7, one portion of which has a rocking motion and this portion is indicated by the character 3. The primary purpose of the portion 8 is to reciprocate the cloth feed plate and has attached thereto a bracket 9 forming a part of the presentinvention and which extends above the bed plate of the sewing machine and has connected thereto a rod H! which rocks back and forth with the portion 8 of the mechanism 1. A pitman rod H is provided at one end with a litting l2 for pivotally and 'adjustably-connectin'g the pitman rod on the rod which enters an opening or eye M of a head 15 forming an integral part of a slidable member 56 used in the feed mechanism of the present invention.

A hemmer or cloth folding device I? is detachably secured on a bracket I8 and the latter is adjustably secured on the bed plate of the sewing machine by a set screw 19 threaded in the bed plate and passing through a slot 26 in said bracket. The hemmer ii is supported by the bracket over the bed plate in front of the presser foot and needle of the sewing machine and also in front of the cloth feed mechanism t of said sewing machine. The purpose of the hemmer is that when cloth is to be hemmed by the sewing machine the cloth first passes through the hemmer which folds one edge of the cloth upon itself so that on the cloth being acted upon by the needle, presser foot and cloth feeding mechanism of the sewing machine the folded cloth will be stitched into a hem.

In the making of clothbags of the character heretofore mentioned it is the practice of hemming a strip of cloth in many yards of length and after the strip of cloth has been hemmed it is the practice to cut the strip of cloth into many pieces of a length so that a bag of a predetermined size may be made from the piece of cloth. After the cutting of the strip of the cloth into mariy pieces and the sewing of said pieces into bag formation or just prior to the sewing of the pieces into bag formation, it has been the practice to thread through the hem of the piece a tying cord. This threading has been done manually requiring considerable time on the part of the operator, Through the employment of the present invention, a portion of which has been heretofore described and the remaining portion which will now be described, operating in conjunction with the hemmer and will lay the string into the hem as the latter is formed in the strip of fabric with a surplus amount of string so that when the fabric is cut into pieces to make the bags sufficient string will be in the hem of each piece to provide a tying string of sufficient length for the closing of the bag after the construction of the bag from the piece out from the strip of fabric.

The present invention being timed with the cloth feed mechanism and operating in conjunction with the hemmer will lay into the hem a selected amount of string as fast as the strip of fabric is hemmed by the sewing machine.

The hemmer l1 includes in its construction a plate 2! which has a portion bent upon itself to form a substantially conical shaped throat 22 through which the cloth passes on its way to the presser foot and needle of the machine to bring about folding of one edge of the cloth upon itself. The plate 2| is further bent to form the attaching portion 23 which is secured onto the bracket l8 and has formed thereon a channeled supporting member 25 which slidably supports the reciprocal feed member l5. Formed integrally with theguide member 2A and in advance of the plate 2! is a connecting plate 25 which also is formed onto a string guide 26 for supporting a portion thereof centrally of the throat 22 of the hemmer and spaced from the walls of the throat with one end projecting a limited distance beyond the restricted end of the throat for the discharge of the string from the guide. The string is indicated by the character 21 and is received from a suitable supply (not shown) and passes into the guide at one end thereof and is force the string against said wall of the guide.

The spring rod 28 further includes an angularly related portion 3! acting as a cam member engaged by a string feed dog 32 in the form of a spring rod having one end fixed on the head l5 of the member l6 and its other end angularly disposed and sharpened, as shown at 33, to engage the string for feeding the string through the string guide in one direction or toward the discharge end of the string guide by the sliding movement of the member [5 in one direction. The movement of the dog 32 in this direction of feeding the string outwardly of the discharge end of the guide engages the cam face 3| of the holding dog 39 and flexes the latter to free the holding dog 38 from the string so that said string may move outwardly of the discharge end of the string guide. A movement of the feed dog 32 in a reverse direction it is disengaged from the cam face 3! of the holding dog 30 and the latter springs into engagement with the string and grips the latter to prevent a reverse movement of the string by the feed dog 32 moving in the reverse direction.

It will be seen from the foregoing description when taken in connection with the drawings that the string 21 will be fed through the string guide in a step by step movement with the string leaving the discharge end of the guide in a crimped form due to the action of the holding dog 30 on the string. It further will be seen that in order to produce this crimped portion in the string that the holding dog 30 holds the string in the string guide during a portion of the stroke of the feed dog 32 toward the discharge end of the string guide so that on the feed dog releasing the holding dog 36 from the string, the latter on leaving the guide will be in crimped formation.

Further, it will be seen that through the adjustment of the fitting I2 on the rod [0 the stroke of the pitman H can be varied in length, consequently varying the length of movement of the feed dog and thereby permit the amount of string ejected from the guide during each feed stroke of feed dog to be varied.

The string feed mechanism of the present invention as shown and described in the drawings operates in timed relation with the cloth feed mechanism 6 of the sewing machine so that as the cloth is advanced in the hemming of said cloth the string will be injected into the hem of the cloth as saidhem is formed and stitched.

It is preferable that the string guide or the portion thereof extending into the conical shaped throat of the hemmer be of substantially oblong shape in cross section or end view and when it is desired to pass two strings into a hem as the latter is formed in the fabric it is only necessary to increase the size of the string guide to accommodate the two strings, as shown in Figure 10, and to increase the width of the holding and feeding dogs. The laying of double strings into the hem of the fabric is clearly shown in Figure 11 with each string crimped to provide the surplus amount of string in the hem sufl icient to permit, when the fabric is cut to form a bag,

sufiicient length to the end portions of the strings to permit them to be tied together to form draw strings for the mouth of the bag.

By referring to Figure 6 it will be noted that the hemmer I1 is really constructed from two plates secured together, one being the attaching plate 23 and the other the plate 2!, the latter being bent upon itself to form the substantially conical-shaped throat, the receiving end of the throat being shown in Figure 5 with the string guide located therein. Also this view shows the cloth being folded by the hemmer with the cloth passing over the plate 2| and through the conical shaped throat and under the plate 23. The plates 2! and 23 are welded or otherwise secured together in the constructing of the hammer.

It is believed that the foregoing description, when taken in connection with the drawings, will fully set forth the construction and advantages of this invention to those skilled in the art to which such a device relates, so that further detailed description will not be required.

Having thus described our invention, what We claim is:

1. In combination with a hemmer having a substantially conical shaped throat, a channeled string guide extending through the throat and adapted to receive string from a supply, a feed dog operating in the string guide to engage and feed the string from the discharge end of the string guide, a spring type holding dog engaging the string in the guide adjacent the discharge end of the latter and having a cam face to be engaged by the feed dog on the latter moving on its string feeding stroke to disengage the holding dog from the string, and means for operating the feed dog.

2. In combination with a hemmer having a substantially conical shaped throat, a channeled string guide extending through the throat and adapted to receive string from a supply, a feed dog operating in the string guide to engage and feed the string from the discharge end of the string guide, a spring type holding dog engaging the string in the guide adjacent the discharge end of the latter and having a cam face to be engaged by the feed dog on the latter moving on its string feeding stroke to disengage the holding dog from the string, a supporting member connected to the string guide and supported by the hemmer, an operating member slidably mounted in the supporting member and having a feed dog connected thereto, and means for reciprocating said member.

3. In combination with a hemmer having a substantially conical shaped throat, a channeled string guide extending through the throat and adapted to receive string from a supply, a feed dog operating in the "string guide to engage and feed the string from the discharge end of the string guide, a spring type holding dog engaging the string in the guide adjacent the discharge end of the latter and having a cam face to be engaged by the feed dog on the latter moving on its string feeding stroke to disengage the holding dog from the string, a supporting member connected to the string guide and supported by the hemmer, an operating member slidably mount-ed in the supporting member and having a feed dog connected thereto, a pitman connected to said member, a rod having said pitman pivotally and adjustably connected thereto for imparting reciprocation to said pitman, and means for connecting said rod to a reciprocating mechanism of a fabric feed device of the sewing machine.

4. In combination with a hemmer having a substantially conical-shaped throat, a channeled string guide extending through the throat and adapted to receive string from a supply, a feed dog operating in the string guide to engage and feed the string from the discharge end of the string guide, a spring type holding dog including a hook-shaped end engaging the string in the guide adjacent the discharge end of the latter and having a cam face to be engaged by the feed dog on the latter moving into its string feeding stroke to disengage the holding dog from the string, and means for operating the feed dog.

DWIGHT J. DUNCAN. RICHARD D. PROPHET. 

